Dell Venue 11 Pro no bootable devices found

After installing Ubuntu on my Dell Venue 11 Pro 7140, it failed to boot with the message "no bootable devices found". I tried several times, from both BIOS Setup and Linux efibootmgr, to add a boot entry to start grub (/EFI/ubuntu/shimx64.efi)... but every time I rebooted this was no longer shown as a boot option.

It turns out that the BIOS specifically looks for a file /EFI/boot/bootx64.efi to determine if a hard drive is bootable. To work around this, you can create a dummy file /EFI/boot/bootx64.efi on the EFI system partition of the drive. The BIOS will then automatically create a boot option for the drive, which you should disable to prevent it trying to run the empty file. After this the normal Linux boot entry should work.

The full instructions can be found at [1]; the process is the same as for Dell XPS 13.